Inflammatory bowel disease (IBD) is a chronic, relapsing and remitting gastrointestinal inflammatory disease that affects approximately 7 million people worldwide [1]. Improving patients’ quality of life (QoL) is one of the main treatment goals for IBD [2]. Except for intestinal inflammation (abdominal pain and diarrhoea), some extraintestinal symptoms can also result in a decline in QoL. Therefore, there is a growing awareness among practitioners and nurses that appropriate care must involve an understanding of not only the treatment of intestinal manifestations but also the management of extraintestinal manifestations [3]. Fatigue, as a persistent weakness resulting in a decreased capacity for physical and mental work [4], is one of the most important extraintestinal clinical problems in patients with IBD, with a prevalence of 21%–83% [5]. More than half of IBD patients indicate that substantial fatigue could impair their QoL, social functioning, employment and even speed relapse and rehospitalisation [5,6]. In addition to fatigue, poor sleep, which is also an unrecognised but important extraintestinal manifestation, can also contribute to decreased activity in daily life, severity of disease and frequent IBD rehospitalisation [[7], [8], [9]].

Given the multifactorial aetiology of fatigue and sleep disorders involving physical and psychosocial processes, both pharmacological and nonpharmacological methods can be utilised to treat fatigue and sleep disorders in patients with IBD [5,7]. Compared with pharmacological therapy, nonpharmacological therapy is safer and has fewer side effects [10].

As a form of alternative and complementary medicine (ACM), aromatherapy is a holistic intervention for fatigue and sleep disorders [11]. Aromatherapy refers to the application of essential oils extracted from the vapour of the volatile essence of plants [12], which can work through being absorbed by the body in two ways: smearing and inhalation. In the process of aromatic smearing, essential oils can enter through the subcutaneous tissue into the capillaries and pass the blood–brain barrier within the bloodstream, thus affecting the entire central nervous system [12]. In the process of aromatic inhalation, essential oil has effects on endocrine and immune systems through being detected by the nervus olfactory system and directly connected via the intracranial olfactory bulb to the limbic system in the hypothalamus and thus to the autonomic nervous system. Meanwhile, volatile oil can also be inhaled through the alveoli into the capillary blood vessels. Many essential oils can be used in aromatherapy. Lavender essential oil (LEO) is commonly regarded as an effective aromatherapy oil, and it has a long history of use in traditional medicine as a natural remedy for various inflammatory disorders. LEO, containing high concentrations of the monoterpenoids linalool, linalyl-acetate, 1,8-cineole, camphor, and terpinen-4-ol, has regulatory effects on the inflammatory response by inhibiting the production of several bacteria-induced proinflammatory cytokines, such as IL-1ɑ, IL-1β and IL-6, by macrophages [14]. Similarly, bergamot essential oil (BEO) is also a common essential oil used in aromatherapy. The volatile compounds account for 93–96% of BEO, containing monoterpenes and discrete quantities of linalool and linalyl acetate. Previous literature suggests that BEO can play an important role in many areas, such as in the nervous system, cardiovascular health, inflammation, diabetes bone metabolism, and skin [15]. Additionally, aromatherapy with orange can also influence anxiolytic and sedative effects. Orange essential oil is often not used alone, but often in combination with BEO or LEO.

Many studies have revealed that aromatherapy has beneficial and safe effects on psychological stress, anxiety, depression and cognitive functions [[16], [17], [18], [19]]. In recent years, aromatherapy has been widely studied in haemodialysis patients [20,21], puerperae [22], and elderly individuals [23]. However, due to the changes in lifestyle and nutritional status caused by IBD, is the effect of aromatherapy on IBD the same as in previous studies on other diseases? There are a limited number of studies evaluating the effect of aromatherapy in IBD patients. It is essential to produce evidence-based data for practitioners and nurses to use aromatherapy to decrease fatigue and sleep disorders and improve QoL in IBD patients. Therefore, this study is important in terms of revealing the need for more research. The aim of this study was to evaluate feasibility and effect of aromatherapy (smearing and inhalation) on fatigue, sleep quality and QoL in patients with IBD.